1. Field of the Invention
The invention relates to a device and method for sufficiently seaming together the edge portions of adjacent panels so that a rotary seaming device can be applied to the panels to provide a continuous connecting seam.
2. Prior Art and Backround
It is known to construct continuous arch metal buildings with adjacent curved building panels which are seamed together at their adjacent edges. See for example U.S. Pat. No. 3,902,288 (1975) owned by MIC Industries, Inc.
In connection with seaming of panels for such metal buildings rotary seamer devices have been used. See for example the seaming devices disclosed in U.S. Pat. Nos. 3,875,642 (1975) and 4,470,186 (1984) and 4,726,107 (1988).
The seamers seam adjacent panel side edge portions together and hold them together. As to the panels, each panel comprises a main portion from which the side edge portion extends vertically. The first panel includes an outturned side edge portion having an upwardly extending outwardly turned flange portion and a downturned terminal portion, forming an inverted U-shaped channel. In other words, a first section extends upwardly from the panel, a second section extends outward laterally from the first section, and a third section extends downward from the second section to form the U-shaped channel. The second panel includes an inturned side edge portion having an inwardly turned flange portion disposed inside the U-shaped channel of the first panel. This inturned side edge portion has a first section extending upwardly from the panel and a second section extending laterally inward from the first section; these sections respectively fit in the first and second sections of the first panel. See, e.g. the following patents owned by MIC Industries, Inc. 3,967,430 (1976) and 4,505,084 (1984).
As stated above, the downturned terminal portion of the one panel must be bent under toward the inturned portion of the other panel before the rotary seamer can effectively travel along the panels and forms the continuous final seam. This has led to the use of manual devices to bend the downturned terminal portion so that rotary seamers can be applied to form the final seam.
Such manual crimping devices utilize a lever-type action to bend this downturned portion to a position which permits application of a rotary seamer to the panels. An inherent problem with such devices is that their effectiveness is limited by the amount of power which can be applied by the user. This in turn is limited to the mechanical advantage provided by the device. The use of metal panels having increased strength and thickness in modern structures adds to the difficulty in using such lever-type devices. This can lead to inadequate crimping as well as worker fatigue and inefficiency since these manual devices must be used every time a new panel is started.
Furthermore, additional tabs, or edge portions, are often seamed in the building panels to support various structures such as roofing panels, lighting fixtures, ventilation ducts or the like. This can add to thickness of the edge portions which must be folded before a rotary seaming device can be applied.
Another problem arising from the use of these manual crimping devices is undesirable scratching or marring of the surfaces of the panels being seamed together. The use of these manual lever-type, or scissor-type devices can often damage the panel surfaces when applied to the side edge portions.